Liquid formulations of tumor necrosis factor-binding proteins

ABSTRACT

The invention relates to a stable, pharmaceutically acceptable, aqueous formulation of TNF-binding protein, comprising a TNF-binding protein, a buffer and an isotonicity agent.

This application is a Continuation of U.S. application Ser. No. 10/547,307, filed Oct. 11, 2006, which is the National Stage of PCT/EP04/50118, filed Feb. 11, 2004, which claimed priority to European application no. 03100505.1, filed Feb. 28, 2003; of which all of the disclosures are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

This invention relates to liquid, stable formulations of TNF-Binding Proteins.

BACKGROUND OF THE INVENTION

Tumor necrosis factor-alpha (TNF-α), a potent cytokine, elicits a broad spectrum of biologic responses, which are mediated by binding to a cell surface receptor. Stauber et al. “Human tumor necrosis factor-alpha receptor: purification by immunoaffinity chromatography and initial characterization” (J. Biol. Chem. 263: 19098-19104, 1988) isolated the receptor for human TNF-alpha from a human histiocytic lymphoma cell line. Hohmann et al. “Two different cell types have different major receptors for human tumor necrosis factor (TNF-alpha)” (J. Biol. Chem. 264: 14927-14934, 1989) concluded that there are 2 different proteins that serve as major receptors for TNF-alpha, one associated with myeloid cells and one associated with epithelial cells.

Using monoclonal antibodies, Brockhaus et al. “Identification of two types of tumor necrosis factor receptors on human cell lines by monoclonal antibodies” (Proc. Nat. Acad. Sci. 87: 3127-3131, 1990) obtained evidence for 2 distinct TNF-binding proteins, both of which bind TNF-alpha and TNF-beta specifically and with high affinity. Gray et al. “Cloning of human tumor necrosis factor (TNF) receptor cDNA and expression of recombinant soluble TNF-binding protein” (Proc. Nat. Acad. Sci. 87: 7380-7384, 1990) isolated the cDNA for one of the receptors. They found that it encodes a protein of 455 amino acids that is divided into an extracellular domain of 171 residues and a cytoplasmic domain of 221 residues. Aggarwal et al. “Characterization of receptors for human tumour necrosis factor and their regulation by gamma-interferon” (Nature 318: 665-667, 1985) showed that tumor necrosis factors alpha and beta initiate their effects on cell function by binding to common cell surface receptors. The TNFA and TNFB receptors have different sizes and are expressed differentially in different cell lines (see Hohmann et al., 1989; and Engelmann et al. “Two tumor necrosis factor-binding proteins purified from human urine: evidence for immunological cross-reactivity with cell surface tumor necrosis factor receptors.” (J. Biol. Chem. 265: 1531-1536, 1990)).

TNF-α-R, referred to by some as TNFR55, is the smaller of the 2 receptors. cDNAs for both receptors have been cloned and their nucleic acid sequence determined (see Loetscher et al. “Molecular cloning and expression of the human 55 kd tumor necrosis factor receptor.” (Cell 61: 351-359, 1990); Nophar et al. “Soluble forms of tumor necrosis factor receptors (TNF-Rs): the cDNA for the type I TNF-R, cloned using amino acid sequence data of its soluble form, encodes both the cell surface and a soluble form of the receptor” (EMBO J. 9: 3269-3278, 1990); Schall et al. “Molecular cloning and expression of a receptor for human tumor necrosis factor.” (Cell 61: 361-370, 1990); Smith et al. “A receptor for tumor necrosis factor defines an unusual family of cellular and viral proteins.” (Science 248: 1019-1023, 1990).

Proteins are known to undergo several degradative pathways, especially deamidation, aggregation, clipping of the peptide backbone and oxidation. Many of these reactions can be slowed significantly by removal of water from the protein.

However, the development of an aqueous formulation for drug proteins has the advantages of eliminating reconstitution errors, thereby increasing dosing accuracy, as well as simplifying the use of the product clinically, thereby increasing patient compliance. Thus, it is an objective of this invention to provide an aqueous formulation of TNF-binding proteins, which provides acceptable control of degradation products, is stable to vigorous agitation (which induces aggregation), and is resistant to microbial contamination (which allows “multiple use” or “multi-dose” packaging).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows linear regression lines for onercept formulated bulk at 5 mg/ml and 50 mg/ml in 10 mM phosphate buffer (stability data at +40±2° C.).

FIG. 2 shows linear regression lines for onercept formulated bulk at 5 mg/ml and 50 mg/ml in 10 mM acetate buffer (stability data at +40±2° C.).

FIG. 3 shows linear regression lines for onercept formulated bulk at 5 mg/ml and 50 mg/ml in 10 mM citrate buffer (stability data at +40±2° C.).

FIG. 4 shows linear regression lines for onercept formulated bulk at 5 mg/ml at different ionic strength (stability data at +40±2° C.).

FIG. 5 shows linear regression lines for onercept formulated bulk at 50 mg/ml at different ionic strength (stability data at +40±2° C.).

FIG. 6 shows linear regression lines for onercept formulated bulk at 5 mg/ml with excipients (stability data at +40±2° C.).

FIG. 7 shows linear regression lines for onercept formulated bulk at 50 mg/ml with excipients (stability data at +40±2° C.).

DESCRIPTION OF THE INVENTION

The main object of the present invention is therefore a stable, pharmaceutically acceptable, aqueous formulation of TNF-binding protein comprising a TNF-binding protein human, a buffer and an isotonicity agent. In one embodiment, the concentration of the buffer is from 5 to 150 mM. In another embodiment, the concentration of the isotonicity agent is from 5 to 50 mM.

Preferably the pH of the solution is kept between 6 and 7 by using a buffer. The buffer can be any pharmaceutically acceptable buffer, which is able to maintain such a pH. Preferably it is phosphate buffer.

The isotonicity agent may be any pharmaceutically acceptable agent, which includes any neutral salt or sugar. For example it can be sodium chloride or mannitol.

A preservative may be included in the formulation to retard microbial growth and thereby allow “multiple use” or “multi-dose” packaging of the TNF-binding protein. Preservatives include phenol, benzyl alcohol, meta-cresol, methyl paraben, propyl paraben, benzalconium chloride, and benzethonium chloride. The preferred preservatives include m-cresol and benzyl alcohol.

The liquid formulations of the invention can also be freeze-dried or lyophilised, if needed.

According to the present invention “TNF-binding proteins” means any protein, which has an affinity for TNF-alpha or TNF-beta and/or a protein, which comprises in full or in part the extra-cellular, soluble fragment of a protein belonging to the TNF receptors family.

Some examples of members of the TNF receptor family are the following:

-   -   Tumor Necrosis Factor Receptor 1 (TNFR1), also called Tumor         Necrosis Factor Receptor Superfamily, Member 1A (TNFRSF1A), or         Tumor Necrosis Factor-alpha Receptor (TNFAR) or TNFR 55-KD or         TNFR 60-KD (see description at OMIM*191190         http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMIM)     -   Tumor Necrosis Factor Receptor 2 (TNFR2), also called Tumor         Necrosis Factor Receptor Subfamily, Member 1B (TNFRSF1B), or         Tumor Necrosis Factor-beta Receptor (TNFBR) or TNFR 75-KD or         TNFR 80-KD (see description at OMIM*191191);     -   OX40 Antigen (OX40), also called Tumor Necrosis Factor Receptor         Superfamily, Member 4 (TNFRSF4), or Tax-Transcriptionally         Activated Glycoprotein 1 Receptor (TXGP1L) or Lymphoid         Activation Antigen ACT35 (ACT35) or OD134 (see description at         OMIM*600315);     -   CD40L Receptor (CD40), also called Tumor Necrosis Factor         Receptor Superfamily, Member 5 (TNFRSF5) or B-cell surface         antigen CD40, or CDw40 or Bp50 (see description at Swiss-Prot         Entry No. P25942);     -   FASL Receptor (FAS), also called Tumor Necrosis Factor Receptor         Superfamily, Member 6 (TNFRSF6), or Apoptosis-Mediating Surface         Antigen FAS or Apo-1 Antigen or OD95 (see description at         Swiss-Prot Entry No. P25445);     -   Decoy Receptor 3 (DcR3), also called Tumor Necrosis Factor         Receptor Superfamily, Member 6B (TNFRSF6B) or Decoy Receptor for         FAS Ligand or M68 (see description at Swiss-Prot Entry No.         095407);     -   OD27 Antigen (CD27), also called Tumor Necrosis Factor Receptor         Superfamily, Member 7 (TNFRSF7) or T-Cell Activation Antigen         S152 (S152) (see description at OMIM*602250);     -   Lymphoid Activation Antigen CD30 (CD 30), also called Tumor         Necrosis Factor Receptor Superfamily, Member 8 (TNFRSF8) (see         description at OMIM*153243)     -   Induced By Lymphocyte Activation (ILA), also called Tumor         Necrosis Factor Receptor Superfamily, Member 9 (TNFRSF9) or         OD137 (see description at OMIM*602250);     -   Death Receptor 4 (DR4), also called Tumor Necrosis Factor         Receptor Superfamily, Member 10A (TNFRSF10A), or TNF-Related         Apoptosis-Inducing Ligand Receptor 1 (TRAILR1) or APO2 (see         description at OMIM*603611);     -   Death Receptor 5 (DR5), also called Tumor Necrosis Factor         Receptor Superfamily, Member 10B (TNFRSF10B), or TNF-Related         Apoptosis-Inducing Ligand Receptor 2 (TRAILR2) or Killer/DR5 or         TRICK2 (see description at OMIM*603612);     -   Decoy Receptor 1 (DCR1), also called Tumor Necrosis Factor         Receptor Superfamily, Member 10C (TNFRSF10C), or TNF-Related         Apoptosis-Inducing Ligand Receptor 3 (TRAILR3), or TRAIL         Receptor Without An Intracellular Domain (TRID) (see description         at OMIM*603613);     -   Decoy Receptor 2 (DCR2), also called Tumor Necrosis Factor         Receptor Superfamily, Member 10D (TNFRSF10D) or TNF-Related         Apoptosis-Inducing Ligand Receptor 4 (TRAILR4) or TRAIL Receptor         With A Truncated Death Domain (TRUNDD) (see description at         OMIM*603014);     -   Receptor Activator of NF-KAPPA-B (RANK), also called Tumor         Necrosis Factor Receptor Superfamily, Member 11A (TNFRSF11A), or         Osteoclast Differentiation Factor Receptor (ODFR) or PDB2 or         TRANCER (see description at OMIM*603499);     -   Osteoprotegerin (OPG), also called Tumor Necrosis Factor         Receptor Superfamily, Member 11B (TNFRSF11B) or         Osteoclastogenesis Inhibitory Factor (OCIF) (see description at         OMIM*602643);     -   Death Receptor 3 (DR3), also called Tumor Necrosis Factor         Receptor Superfamily, Member 12 (TNFRSF12), or APO3 or         Lymphocyte-Associated Receptor of Death (LARD) (see description         at OMIM*603366);     -   Transmembrane Activator And Caml Interactor (TACI), also called         Tumor Necrosis Factor Receptor Superfamily, Member 13B         (TNFRSF13B) (see description at OMIM*604907);     -   BAFF Receptor (BAFFR), also called Tumor Necrosis Factor         Receptor Superfamily, Member 13C (TNFRSF13C), or B         Cell-Activating Factor Receptor (see description at         OMIM*606269);     -   Herpesvirus Entry Mediator (HVEM), also called Tumor Necrosis         Factor Receptor Superfamily, Member 14 (TNFRSF14), or         Herpesvirus Entry Mediator A (HVEA) or TR2 (see description at         OMIM*602746);     -   Nerve Growth Factor Receptor (NGFR), also called Tumor Necrosis         Factor Receptor Superfamily, Member 16 (TNFRSF16) or p75(NTR)         (see description at OMIM*162010);     -   B-Cell Maturation Factor (BCMA), also called Tumor Necrosis         Factor Receptor Superfamily, Member 17 (TNFRSF17) or BCM (see         description at OMIM*109545);     -   Glucocorticoid-Induced TNFR-Related Gene (GITR), also called         Tumor Necrosis Factor Receptor Superfamily, Member 18         (TNFRSF18), or Activation-Inducible TNFR Family Member (AITR)         (see description at OMIM*603905);     -   TRADE, also called Tumor Necrosis Factor Receptor Superfamily,         Member 19 (TNFRSF19), or Toxicity and JNK Inducer or TROY or TAJ         (see description at Swiss-Prot Entry No. Q9NS68);     -   X-linked Ectodyplasin-A2 Receptor (XEDAR), also called EDA-A2         receptor (see description at Swiss-Prot Entry No. Q9HAV5) and     -   DEATH RECEPTOR 6 (DR6), also called Tumor Necrosis Factor         Receptor Superfamily, Member 21 (TNFRSF21) (see description at         OMIM*605732).

In one embodiment, the TNF-binding protein is TBP-1. In another embodiment, the TNF-binding protein is TBP-2. According to a preferred embodiment of the invention the TNF-binding protein is selected between recombinant h-TBP-1 (recombinant, extracellular, soluble fragment of human TNF Receptor-1, comprising the amino acid sequence corresponding to the 20-180 amino acids fragment of Nophar et al.), whose International Non-proprietry Name (INN) is “onercept”, and recombinant h-TBP-2 (recombinant, extracellular, soluble fragment of TNF Receptor-2, comprising the amino acid sequence corresponding to 23-257 of Smith et al.). Most preferably it is recombinant hTBP-1 (r-hTBP-1). For all the other proteins the soluble, extracellular domain is indicated in the corresponding Swiss-Prot entry.

In a different embodiment, the concentration of TNF-binding protein is comprised between 5 and 170 mg/ml.

In one embodiment, the formulation comprises TBP-1, 0.1 M sodium phosphate buffer at pH=6.5 and 0.025 M sodium chloride. Another embodiment is directed to a process for the preparation of a liquid pharmaceutical formulation, comprising the dilution of the TNF-binding protein with a solution of excipients. Yet, another embodiment is directed to a presentation form of the liquid pharmaceutical formulation, hermetically sealed in sterile conditions in a contained appropriate for storage prior to use.

In the attempt to find a stable, liquid formulation, the effect of pH/buffer, ionic strength and excipients was evaluated. The description that follows reports on experiments carried out with TBP-1 (onercept).

Examples Materials

Onercept drug substance (supplied by Istituto di Ricerca Cesare Serono, Ardea, IT)

Acetonitrile (Merck)

Acetic acid glacial (Merck) Ammonium sulphate (Merck) Citric acid (Merck) D(+)-Glucose monohydrate (Merck)

D(+)-Mannitol (Merck)

ortho-Phosporic acid (Merck)

Saccharose (Merck)

Sodium azide (Merck) Sodium chloride (Merck) Sodium hydroxide (Merck) Sodium sulphate anhydrous (Merck) Sodium dihydrogen phosphate monohydrate (Merck) di-Sodium hydrogen phosphate dihydrate (Merck) Trifluoroacetic acid (Baker)

Equipment

HPLC systems (Waters) Calibrated pipettes (Gilson) Stainless steel holders (Sartorius) pH meters (mod. 713, Metrohm)

Osmometer (Osmomat 030-D, Gonotec)

Membrane filters 0.45 μm and 0.22 μm (cod. HVLP04700 and GWVP04700, Millipore)

Column TSK gel G2000 SWXL (cod. 08540, TosoHaas) Column TSKgel Phenyl-5PW Glass 0.8 ID×7.5 cm (cod 08804, TosoHaas) Primary Packaging Material

Borosylicate type I glass vials (DIN 2R, Nuova Ompi) Flurotec rubber stoppers (S2F452, D777-1, B2-40, Daikyo Seiko) Borosilicate Type I glass syringes (HYPAK SCF syringe barrels with fixed needle and needle shield—SCF 1.0 mL long W 7974 grey—Becton Dickinson) Flurotec stoppers, 1 mL-1 BG B2-40c FLT 4023/50 gr (Daykio) Bromobutyl stoppers (HYPAK SCF plunger stoppers—BSCF 1.0 mLL 4023/50 grey (Becton Dickinson)

Analytical Tests and Methods

The following analytical tests and methods were used:

pH (potentiometric)

appearance (colour, clarity/opalescence, particles) (visual inspection)

purity and assay by SE-HPLC (working instruction TF 08/01)

purity by HI-HPLC (working instruction TF 09/01)

osmolality (cryoscopic measurement), at time zero only

bioassay

First of all, the effect of pH/buffer, ionic strength and excipients was evaluated. The compatibility with stoppers (coated and uncoated) was evaluated as well. Once selected the best conditions, the following three strengths were investigated in pre-filled syringes:

10 mg/mL

50 mg/mL

60 mg/mL

A stability study was performed up to 3 months after storage at +5±3° C.; +25±2° C. and +40±2° C. and the following tests were executed:

pH

appearance (colour, clarity/opalescence, particles; by visual inspection)

assay (by SE-HPLC)

purity (by SE-HPLC)

purity (by HI-HPLC)

osmolality (at time zero only)

bioassay

pH Effect

In order to test the effect of pH/buffer, solutions of onercept at 5 mg/ml and 50 mg/ml were prepared by dilution of the drug substance in the following 10 mM buffers at different pH:

1. sodium acetate at pH 4, 5 and 6

2. sodium citrate at pH 4, 5, 6 and 7

3. sodium phosphate at pH 5, 6, 7 and 8

The solutions (about 20 ml/batch) were filled into 3 ml glass vials (1 ml filling volume), capped, stoppered and stored at +5±3° C., +25±2° C. and +40±2° C. to be analysed weekly up to 1 month. Results were as shown by the Graphs of FIGS. 1, 2 and 3 and by Table 1:

TABLE 1 Onercept formulated bulk at 5 mg/ml and 50 mg/ml in 10 mM buffers (losses in purity by SE-HPLC at +40 ± 2° C.) Loss in purity (%) Slopes (% degr./week) after 1 month Formulation PHO* CITR.* ACE* PHO* CITR.* ACE* 5 mg/ml at / −0.07 −0.10 / −0.3% −0.4% pH = 4.0 5 mg/ml at −0.33 −0.24 −0.32 −1.3% −0.9% −1.3% pH = 5.0 5 mg/ml at −0.17 −0.10 −0.17 −0.7% −0.4% −0.7% pH = 6.0 5 mg/ml at −0.40 −0.15 / −1.6% −0.6% / pH = 7.0 5 mg/ml at −8.45 / / −33.8%  / / pH = 8.0 50 mg/ml at / −0.68 −1.56 / −2.7% −6.2% pH = 4.0 50 mg/ml at −1.79 −0.95 −1.79  7.2% −3.8% −7.2% pH = 5.0 50 mg/ml at −0.65 −0.50 −0.70 −2.6% −2.0% −2.8% pH = 6.0 50 mg/ml at −0.86 −0.78 / −3.4% −3.1% / pH = 7.0 50 mg/ml at −10.88  / / −43.5%  / / pH = 8.0 *PHO = sodium phosphate buffer, CITR. = sodium citrate buffer, ACE = sodium acetate buffer

As shown by the table above and the graphs a pH dependence is observed both at 5 mg/ml and 50 mg/ml: the minor loss of purity % was observed at pH 6.0 and 7.0 for both strengths. Also citrate and acetate buffer at pH 4.0 had a positive effect on the aggregate content while at pH 8.0 in phosphate buffer a fast degradation path was observed.

No oxidation by HI-HPLC or change in pH or appearance was observed after 1 month storage at +40±2° C.

Ionic Strength Effect

In order to test the effect of various ionic strengths, solutions of onercept at 5 mg/ml and 50 mg/ml were prepared in phosphate buffer at three different molarities (10 mM, 50 mM and 100 mM) at pH 6.0, 6.5, and 7.0 each. The solutions (about 20 ml/batch) were filled into 3 ml glass vials (1 ml filling volume), capped, stoppered and stored at +5±3° C., +25±2° C. and +40±2° C. to be analysed weekly up to 1 month. Results were as shown by the Graphs of FIGS. 4 and 5 and by Table 2:

TABLE 2 Onercept formulated bulk at 5 mg/ml and 50 mg/ml at different ionic strengths (losses in purity by SE-HPLC at +40 ± 2° C.) Loss in purity (%) Slopes (% degr./week) after 1 month Formulation pH 6.0 pH 6.5 pH 7.0 pH 6.0 pH 6.5 pH 7.0 5 mg/ml in −0.18 −0.17 −0.48 −0.7% −0.7% −1.9% 10 mM phosphate buffer 5 mg/ml in −0.15 −0.17 −0.33 −0.6% −0.7% −1.3% 50 mM phosphate buffer 5 mg/ml in −0.13 −0.16 −0.37 −0.5% −0.6% −1.5% 100 mM phosphate buffer 50 mg/ml in −0.53 −0.57 −1.07 −2.1% −2.3% −4.3% 50 mM phosphate buffer 50 mg/ml in −0.39 −0.50 −1.21 −1.6% −2.0% −4.5% 100 mM phosphate buffer

As shown by the graphs and the table above the extent of aggregation is not affected by the buffer concentration: pH 7.0 has a negative effect on purity % at each buffer strength while a minor loss in purity was observed both at pH 6.0 and 6.5. No oxidation by HI-HPLC nor change in pH or appearance was observed after 1 month storage at +40±2° C.

Other Excipients (Stabilizers) Effect

In order to test the effect of various excipients, solutions of onercept at 5 mg/ml and 50 mg/ml were prepared in phosphate buffer 40 mM at pH 6.0 and 6.5 and brought to isotonicity with sodium chloride, mannitol, glucose and saccharose. The solutions (about 20 ml/batch) were filled into 3 ml glass vials (1 ml filling volume), capped, stoppered and stored at +5±3° C., +25±2° C. and +40±2° C. to be analysed weekly up to 1 month.

Results were as shown by the Graphs of FIGS. 6 and 7 and by Table 3:

TABLE 3 Onercept formulated bulk at 5 mg/ml and 50 mg/ml with excipients (losses in purity by SE-HPLC at +40 ± 2° C.) Slopes Loss in purity (%) (% degr./week) after 1 month pH = pH = pH = pH = Formulation 6.0 6.5 6.0 6.5 5 mg/ml with sodium chloride −0.10 −0.10 −0.4% −0.4% 5 mg/ml with mannitol −0.10 −0.08 −0.4% −0.3% 5 mg/ml with saccharose −0.17 −0.20 −0.7% −0.8% 5 mg/ml with glucose −1.09 −2.7 −4.4% −10.8 50 mg/ml with sodium chloride −0.44 −0.42 −1.8% −1.7% 50 mg/ml with mannitol −0.48 −0.43 −1.9% −1.7% 50 mg/ml with saccharose −0.63 −0.54 −2.5% −2.2% 50 mg/ml with glucose −4.66 −6.97 −18.6% −27.9%

As shown by the Graphs and the Table above sodium chloride and mannitol had the same behaviour as isotonicity agents. Consequently, sodium chloride was to selected being already present in the drug substance solution. Further, no pH shift occurred after one month storage at +40±2° C. while a modified pattern on the chromatographic profile was observed by HI-HPLC for the onercept formulations containing glucose and saccharose as stabilizers.

From all these results, the surprising conclusion comes that the most stable liquid formulations are those excipients, which are normally used as stabilizers. Therefore the most stable formulations are those, which contain only an appropriate buffer to dilute the active substance and an isotonicity agent.

In these conditions, the pH range applicable for good stability results is 6.0 to 7, preferably from 6 to 6.5. Isotonicity can be obtained by the addition of adequate amounts of sodium chloride or mannitol, preferably sodium chloride.

Further, analogous experiments have confirmed substantially the same results for strengths of TBP-1 up to 170 mg/ml, as well as for TBP-2.

Examples of Pharmaceutical Production Materials

r-h TBP-1 drug substance; Sodium chloride (Merck); di-Sodium hydrogen phosphate dihydrate (Merck); Sodium dihydrogen phosphate monohydrate (Merck); ortho-Phosphoric acid 85% (Merck); WFI.

Container/Closure

The primary container is a glass syringe with a stainless steel needle and rubber plunger. It is composed of:

Syringe Description:

SCF 1.0 mL long W7974 grey (Becton Dickinson)

Material, Composition:

syringe: borosilicate glass type I

needle: steel

lubricant: DC360, silicone oil-dimethicone

needle shield: elastomer

Plunger Stopper Description:

HYPAK SCF plunger stopper; BSCF 1.0 mLL 4023/50 grey (Becton Dickinson)

Material, Composition:

elastomer: bromobutyl, inert mineral, unconventional curing system

lubricant: DC360, silicone oil-dimethicone

Example of Preparation of r-h TBP-1 Solutions in 0.1 M Sodium Phosphate Buffer, pH=6.5; Sodium Chloride 0.025 M A) Solution of r-h TBP-1 at 14.3 mg/mL For the preparation of a batch of 1 L of finished product, the following quantities are used:

r-h TBP-1 14.3 g Sodium Chloride 1.46 g di-Sodium phosphate dihydrate 10.5 g Sodium dihydrogen phosphate monohydrate 5.68 g B) Solution of r-h TBP-1 at 71.4 mg/mL For the preparation of a batch of 1 L of finished product, the following quantities are used:

r-h TBP-1 71.4 g Sodium Chloride 1.46 g di-Sodium phosphate dihydrate 10.5 g Sodium dihydrogen phosphate monohydrate 5.68 g C) Solution of r-h TBP-1 at 142.9 mg/mL For the preparation of a batch of 1 L of finished product, the following quantities are used:

r-h TBP-1 142.9 g Sodium Chloride 1.46 g di-Sodium phosphate dihydrate 10.5 g Sodium dihydrogen phosphate monohydrate 5.68 g

Method of Preparation

-   -   The liquid drug substance containing r-h TBP-1 is lyophilized         and the resulting powder is collected to be titred.     -   The required quantities of sodium chloride, disodium phosphate         dihydrate and sodium dihydrogen phosphate monohydrate are         dissolved in approximately 800 g of WFI. Their amounts are         calculated taking into account the contribution of salts coming         from the lyophilized drug substance.     -   The pH is checked and adjusted to the value of 6.5±0.2 with         diluted (1:10) ortho-phosphoric acid 85%.     -   The required amount of lyophilized drug substance is added very         slowly under stirring and WFI is added to reach the final weight         (calculated considering the final density of the solution). The         pH is checked and adjusted to pH 6.5±0.2 with diluted         ortho-phosphoric acid, at various steps during compounding.     -   The r-h TBP-1 solution is first pre-filtered through a 0.45 μm         membrane filter followed by a sterile filtration on a 0.22 μm         membrane filter (DURAPORE) under 1.0 atm nitrogen pressure (the         solution at 14.3 mg/mL is not pre-filtered). The sterile         solution is collected into a glass flask. 

1-13. (canceled)
 14. A stable, pharmaceutically acceptable, aqueous formulation, comprising: TNF-binding protein 2 (TPB-2), a citrate buffer keeping the pH between 4 and 7, and an isotonicity agent.
 15. The formulation according to claim 14, in which the buffer keeps the pH comprised between 6 and
 7. 16. The formulation according to claim 14, in which the isotonicity agent is sodium chloride.
 17. The formulation according to claim 14, in which the isotonicity is mannitol.
 18. The formulation according to claim 14, in which the concentration of TNF-binding protein 2 is between 5 and 170 mg/ml.
 19. The formulation according to any of the preceding claim 14, in which the concentration of the citrate buffer is from 5 to 150 mM.
 20. The formulation according to claim 14, in which the concentration of the isotonicity agent is from 5 to 50 mM.
 21. A process for the preparation of a liquid pharmaceutical formulation according to claim 14, said process comprising: diluting the TNF-binding protein with a solution of an excipient.
 22. A presentation form of the liquid pharmaceutical formulation according to claim 14, wherein said presentation form is hermetically sealed in sterile conditions in a container appropriate for storage prior to use. 